Hi All, I want to understand the decay of a spin-1 massive vector particle into two spinless massive particles. Given a massive vector particle V with spin Sz = +1, 0, -1 decays into 2 massive spinless particles. I have to compute the amplitude M but I dont know what should I do with the polarization vectors? Hence my Qs. is that, does the Sz vectors becomes the polarization vectors? is the angular momentum and/or Sz conserve? I am kind of al-confuso because never did any polarized photon-less decay before. any help is much appreciated.